From a2a1766bd4a36d0b034fcf181b5e0d81b4f448c6 Mon Sep 17 00:00:00 2001
From: "Manjunathappa, Prakash" <prakash.pm@ti.com>
Date: Wed, 18 Jul 2012 21:01:56 +0530
Subject: [PATCH] --- yaml --- r: 321088 b: refs/heads/master c:
 deb95c6c958f5ba97b6b89ab18917bf79cb8ce7b h: refs/heads/master v: v3

---
 [refs]                         |  2 +-
 trunk/drivers/video/da8xx-fb.c | 30 ++++++++++++++++++++++++++++++
 2 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/[refs] b/[refs]
index 26590f4a95d0..2f867e7254d2 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 8a81dccd391a3e78f502da137de8fb62020c5809
+refs/heads/master: deb95c6c958f5ba97b6b89ab18917bf79cb8ce7b
diff --git a/trunk/drivers/video/da8xx-fb.c b/trunk/drivers/video/da8xx-fb.c
index 7264aa3b20ff..6b7f2da6f907 100644
--- a/trunk/drivers/video/da8xx-fb.c
+++ b/trunk/drivers/video/da8xx-fb.c
@@ -30,6 +30,7 @@
 #include <linux/clk.h>
 #include <linux/cpufreq.h>
 #include <linux/console.h>
+#include <linux/spinlock.h>
 #include <linux/slab.h>
 #include <linux/lcm.h>
 #include <video/da8xx-fb.h>
@@ -161,6 +162,13 @@ struct da8xx_fb_par {
 	wait_queue_head_t	vsync_wait;
 	int			vsync_flag;
 	int			vsync_timeout;
+	spinlock_t		lock_for_chan_update;
+
+	/*
+	 * LCDC has 2 ping pong DMA channels, channel 0
+	 * and channel 1.
+	 */
+	unsigned int		which_dma_channel_done;
 #ifdef CONFIG_CPU_FREQ
 	struct notifier_block	freq_transition;
 	unsigned int		lcd_fck_rate;
@@ -741,6 +749,7 @@ static irqreturn_t lcdc_irq_handler_rev02(int irq, void *arg)
 		lcdc_write(stat, LCD_MASKED_STAT_REG);
 
 		if (stat & LCD_END_OF_FRAME0) {
+			par->which_dma_channel_done = 0;
 			lcdc_write(par->dma_start,
 				   LCD_DMA_FRM_BUF_BASE_ADDR_0_REG);
 			lcdc_write(par->dma_end,
@@ -750,6 +759,7 @@ static irqreturn_t lcdc_irq_handler_rev02(int irq, void *arg)
 		}
 
 		if (stat & LCD_END_OF_FRAME1) {
+			par->which_dma_channel_done = 1;
 			lcdc_write(par->dma_start,
 				   LCD_DMA_FRM_BUF_BASE_ADDR_1_REG);
 			lcdc_write(par->dma_end,
@@ -796,6 +806,7 @@ static irqreturn_t lcdc_irq_handler_rev01(int irq, void *arg)
 		lcdc_write(stat, LCD_STAT_REG);
 
 		if (stat & LCD_END_OF_FRAME0) {
+			par->which_dma_channel_done = 0;
 			lcdc_write(par->dma_start,
 				   LCD_DMA_FRM_BUF_BASE_ADDR_0_REG);
 			lcdc_write(par->dma_end,
@@ -805,6 +816,7 @@ static irqreturn_t lcdc_irq_handler_rev01(int irq, void *arg)
 		}
 
 		if (stat & LCD_END_OF_FRAME1) {
+			par->which_dma_channel_done = 1;
 			lcdc_write(par->dma_start,
 				   LCD_DMA_FRM_BUF_BASE_ADDR_1_REG);
 			lcdc_write(par->dma_end,
@@ -1053,6 +1065,7 @@ static int da8xx_pan_display(struct fb_var_screeninfo *var,
 	struct fb_fix_screeninfo    *fix = &fbi->fix;
 	unsigned int end;
 	unsigned int start;
+	unsigned long irq_flags;
 
 	if (var->xoffset != fbi->var.xoffset ||
 			var->yoffset != fbi->var.yoffset) {
@@ -1070,6 +1083,21 @@ static int da8xx_pan_display(struct fb_var_screeninfo *var,
 			end	= start + fbi->var.yres * fix->line_length - 1;
 			par->dma_start	= start;
 			par->dma_end	= end;
+			spin_lock_irqsave(&par->lock_for_chan_update,
+					irq_flags);
+			if (par->which_dma_channel_done == 0) {
+				lcdc_write(par->dma_start,
+					   LCD_DMA_FRM_BUF_BASE_ADDR_0_REG);
+				lcdc_write(par->dma_end,
+					   LCD_DMA_FRM_BUF_CEILING_ADDR_0_REG);
+			} else if (par->which_dma_channel_done == 1) {
+				lcdc_write(par->dma_start,
+					   LCD_DMA_FRM_BUF_BASE_ADDR_1_REG);
+				lcdc_write(par->dma_end,
+					   LCD_DMA_FRM_BUF_CEILING_ADDR_1_REG);
+			}
+			spin_unlock_irqrestore(&par->lock_for_chan_update,
+					irq_flags);
 		}
 	}
 
@@ -1299,6 +1327,8 @@ static int __devinit fb_probe(struct platform_device *device)
 	/* initialize the vsync wait queue */
 	init_waitqueue_head(&par->vsync_wait);
 	par->vsync_timeout = HZ / 5;
+	par->which_dma_channel_done = -1;
+	spin_lock_init(&par->lock_for_chan_update);
 
 	/* Register the Frame Buffer  */
 	if (register_framebuffer(da8xx_fb_info) < 0) {